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Q.js examples - Small snippets to understand various api methods in Q.js
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//To run Q.js examples: | |
// 1. Open a new browser tab in Chrome and turn on developer toolbar (or open any http site). | |
// 2. Copy/Paste this gist in the console and hit enter to run the snippets. | |
// Based on the inspiration from samples @ https://github.com/kriskowal/q | |
//////////////////////////////////////////////////////////////////// | |
//////////////////////////////////////////////////////////////////// | |
// Set some global helpers and download Q.js | |
var module = {}; | |
//Promise stubs | |
// The following stubs simulate asynchronous operations that return Q.js promises. | |
// All test cases are dependent on these stubs. | |
// This stub returns a promise which will get resolved after a delay | |
// p_id -> unique identifier | |
// p_ret -> return this value when resolved | |
// p_delay -> custom delay | |
var getResolvedPromise = function(logger, p_ret, p_delay) { | |
var deferred = Q.defer(); | |
Q.delay(p_delay || 30) | |
.done(function() { | |
logger.log("(resolving the promise)"); | |
deferred.resolve(p_ret); | |
}); | |
return deferred.promise; | |
} | |
// This stub returns a promise which will get rejected after a delay | |
// p_id -> unique identifier | |
// p_ret -> return this value when rejected in Error object | |
// p_delay -> custom delay | |
var getRejectedPromise = function(logger, p_ret, p_delay) { | |
var deferred = Q.defer(); | |
Q.delay(p_delay || 30) | |
.done(function() { | |
logger.log("(rejecting the promise)"); | |
deferred.reject(new Error(p_ret || "promise rejected")); | |
}); | |
return deferred.promise; | |
} | |
// This stub returns a promise which will neither resolve/reject but | |
// throws an unhandled exception after some delay | |
// p_id -> unique identifier | |
// p_delay -> custom delay | |
var getExceptionPromise = function(logger, p_ret, p_delay) { | |
var deferred = Q.defer(); | |
Q.delay(p_delay || 30) | |
.done(function() { | |
throw new Error("throwing unhandled exception"); | |
}); | |
return deferred.promise; | |
} | |
var TestRunnerReady = (function() { | |
var testcases = 1; | |
return function(testcaseId, pushFurther) { | |
// takes in the testcaseid and ensures the tests are run staggered | |
// so all related messages are grouped in the console. | |
testcases += pushFurther ? 2 : 1; | |
return Q.delay(testcases++ * 100) | |
.thenResolve({ | |
log: function(p_msg, addBlankLine) { | |
if (typeof p_msg === "string") { | |
addBlankLine && console.log(""); | |
console.log("%s : %s", (testcaseId || ""), p_msg); | |
} else { | |
console.log(p_msg); | |
} | |
}, | |
group: function(p_msg) { | |
console.log(""); | |
console.groupEnd(); | |
console.group(p_msg); | |
} | |
}); | |
} | |
})(); | |
// Download Q.js | |
(function() { | |
var jsFile = document.createElement('script') | |
jsFile.setAttribute("type","text/javascript") | |
jsFile.setAttribute("src", "//cdnjs.cloudflare.com/ajax/libs/q.js/0.9.6/q.js"); | |
jsFile.setAttribute("onload", "console.log('Q.js downloaded'); runQjsExamples();"); | |
document.getElementsByTagName("head")[0].appendChild(jsFile); | |
})(); | |
//////////////////////////////////////////////////////////////////// | |
//////////////////////////////////////////////////////////////////// | |
function runQjsExamples() { | |
// Test cases | |
TestRunnerReady().then(function(logger) { | |
logger.group("1. promise.then, promise.fail"); | |
}); | |
TestRunnerReady("Test Case 1.1").then(function(logger) { | |
logger.log("promise.then with resolved promise.", true); | |
getResolvedPromise(logger, ["return_obj"]) | |
.then(function(res) { | |
logger.log("in promise success handler -"); | |
logger.log(res); | |
}, function (err) { | |
logger.log(err); | |
}); | |
}); | |
TestRunnerReady("Test Case 1.2").then(function(logger) { | |
logger.log("promise.then with rejected promise.", true); | |
getRejectedPromise(logger) | |
.then(function(res) { | |
logger.log(res); | |
}, function (err) { | |
logger.log("in promise error handler -"); | |
logger.log(err); | |
}); | |
}); | |
TestRunnerReady("Test Case 1.3").then(function(logger) { | |
logger.log("promise.then, promise.fail with rejected promise.", true); | |
getRejectedPromise(logger) | |
.fail(function (err) { | |
logger.log("in promise error handler -"); | |
logger.log(err); | |
}); | |
}); | |
TestRunnerReady("Test Case 1.4").then(function(logger) { | |
logger.log("unhandled exception in promise.then handler", true); | |
getResolvedPromise(logger) | |
.then(function(res) { | |
logger.log("throwing error in then"); | |
throw new Error("error in then handler"); | |
}).then(function(res) { | |
logger.log("in handler chain"); | |
}).fail(function(err) { | |
logger.log("in promise error handler -"); | |
logger.log(err); | |
}); | |
}); | |
//////////////////////////////////////////////////////////////////// | |
//////////////////////////////////////////////////////////////////// | |
TestRunnerReady().then(function(logger) { | |
logger.group("2. promise.fin, promise.done, unhandled exceptions"); | |
}); | |
TestRunnerReady("Test Case 2.1").then(function(logger) { | |
logger.log("promise.fin (success scenario)", true); | |
getResolvedPromise(logger, ["success"]) | |
.then(function(res) { | |
logger.log("in promise success handler -"); | |
logger.log(res); | |
}, function (err) { | |
logger.log(err); | |
}).fin(function() { | |
logger.log("in finally"); | |
}); | |
}); | |
TestRunnerReady("Test Case 2.2").then(function(logger) { | |
logger.log("promise.fin (failure scenario)", true); | |
getRejectedPromise(logger) | |
.then(function(res) { | |
logger.log("in promise success handler -"); | |
logger.log(res); | |
}, function (err) { | |
logger.log("in promise error handler -"); | |
logger.log(err); | |
}).fin(function() { | |
logger.log("in finally"); | |
}); | |
}); | |
TestRunnerReady("Test Case 2.3").then(function(logger) { | |
logger.log("promise.done ensures the unhandled exception is re-thrown (from rejected promise)", true); | |
getRejectedPromise(logger) | |
.then(function(res) { | |
logger.log("in promise success handler -"); | |
logger.log(res); | |
}) | |
.done(function() { | |
// Q.js re-throws the unhandled exception when .done is called | |
logger.log("in done (WONT REACH HERE)"); | |
}) | |
.fin(function() { | |
logger.log("in finally (WONT REACH HERE)"); | |
}); | |
}); | |
TestRunnerReady("Test Case 2.4").then(function(logger) { | |
logger.log("unhandled exception in promise stub (can't be trapped in .fail, .done).", true); | |
getExceptionPromise(logger) | |
.fail(function (err) { | |
// won't execute this block | |
logger.log("in fail error handler (won't hit)"); | |
logger.log(err); | |
}).done(null, function(err) { | |
// won't execute this block | |
logger.log("in done error handler (won't hit"); | |
logger.log(err); | |
}); | |
}); | |
TestRunnerReady("Test Case 2.5").then(function(logger) { | |
logger.log("promise.done (catching unhandled exception with fail)", true); | |
getRejectedPromise(logger) | |
.then(function(res) { | |
logger.log("in promise success handler -"); | |
logger.log(res); | |
}) | |
.then(function(res) { | |
throw new Error("throwing error in then handler"); | |
}) | |
.fail(function() { | |
// catch the unhandled exception | |
logger.log("catch the unhandled exception"); | |
}) | |
.fin(function() { | |
logger.log("in finally (MUST be attached before done())"); | |
}) | |
.done(function() { | |
// re-throws the unhandled exception (not catching with fail) | |
logger.log("in done"); | |
}); | |
}); | |
//////////////////////////////////////////////////////////////////// | |
//////////////////////////////////////////////////////////////////// | |
// Chaining | |
TestRunnerReady().then(function(logger) { | |
logger.group("3. CHAINING: promise.then.then.then.fin, promise.then.then.fail.fin"); | |
}); | |
TestRunnerReady("Test Case 3.1").then(function(logger) { | |
logger.log("Chaining (through outer handlers)", true); | |
getResolvedPromise(logger, "Bob") | |
.then(function(name) { | |
logger.log("Name: " + name); | |
return getResolvedPromise(logger, "30"); | |
}).then(function(age) { | |
logger.log("Age: " + age); | |
return getResolvedPromise(logger, "New York") | |
}).then(function(city) { | |
logger.log("City: " + city); | |
}).fin(function() { | |
logger.log("in finally"); | |
}); | |
}); | |
TestRunnerReady("Test Case 3.2", true).then(function(logger) { | |
logger.log("Chaining (through inner handlers - to capture results from different handlers)", true); | |
getResolvedPromise(logger, "Alice") | |
.then(function(name) { | |
logger.log("Name: " + name); | |
return getResolvedPromise(logger, "40") | |
.then(function(age) { | |
logger.log("Name: " + name + " Age: " + age); | |
return getResolvedPromise(logger, "Salt Lake City") | |
.then(function (city) { | |
logger.log("Name: " + name + " Age: " + age + " City: " + city); | |
}) | |
}); | |
}).fin(function() { | |
logger.log("in finally"); | |
}); | |
}); | |
TestRunnerReady("Test Case 3.3").then(function(logger) { | |
logger.log("Chaining (outer handlers) with rejected promise", true); | |
getResolvedPromise(logger, "Mastro") | |
.then(function(name) { | |
logger.log("Name: " + name); | |
return getResolvedPromise(logger, "26"); | |
}).then(function(age) { | |
logger.log("Age: " + age); | |
return getRejectedPromise(logger); | |
}).then(function(city) { | |
logger.log("City: " + city); | |
}).fail(function(err) { | |
logger.log("in fail handler -"); | |
logger.log(err); | |
}).fin(function() { | |
logger.log("in finally"); | |
}); | |
}); | |
TestRunnerReady("Test Case 3.4", true).then(function(logger) { | |
logger.log("Chaining (inner handlers - to capture results from different handlers) with rejected promise", true); | |
getResolvedPromise(logger, "Alice") | |
.then(function(name) { | |
logger.log("Name: " + name); | |
return getResolvedPromise(logger, "40") | |
.then(function(age) { | |
logger.log("Name: " + name + " Age: " + age); | |
return getRejectedPromise(logger) | |
.then(function (city) { | |
logger.log("Name: " + name + " Age: " + age + " City: " + city); | |
}) | |
}); | |
}).fail(function(err) { | |
logger.log("in fail handler -"); | |
logger.log(err); | |
}).fin(function() { | |
logger.log("in finally"); | |
}); | |
}); | |
//////////////////////////////////////////////////////////////////// | |
//////////////////////////////////////////////////////////////////// | |
// Combination | |
TestRunnerReady(null, true).then(function(logger) { | |
logger.group("4. COMBINATIONS: Q.spread, Q.all, Q.allSettled"); | |
}); | |
TestRunnerReady("Test Case 4.1", true).then(function(logger) { | |
logger.log("using Q.spread", true); | |
Q.spread([10, 20, 30], function(a, b, c) { | |
logger.log("Simple usage of spread"); | |
logger.log("values: " + [a,b,c].join(" ")) | |
}); | |
}); | |
TestRunnerReady("Test Case 4.2").then(function(logger) { | |
logger.log("using Q.all", true); | |
Q.all([ | |
getResolvedPromise(logger, "param1"), | |
getResolvedPromise(logger, "param2"), | |
getResolvedPromise(logger, "param3"), | |
]).then(function(results) { | |
logger.log("in then handler"); | |
logger.log("return values from promises are in array - "); | |
logger.log(results); | |
}); | |
}); | |
TestRunnerReady("Test Case 4.3").then(function(logger) { | |
logger.log("combination of promises with spread", true); | |
Q.all([ | |
getResolvedPromise(logger, "param1"), | |
getResolvedPromise(logger, "param2"), | |
getResolvedPromise(logger, "param3"), | |
]).spread(function(result1, result2, result3) { | |
logger.log("in spread handler"); | |
logger.log("return values from promises are captured in params - "); | |
logger.log([result1, result2, result3].join(" ")); | |
}); | |
}); | |
TestRunnerReady("Test Case 4.4").then(function(logger) { | |
logger.log("mixing array of promises and spread", true); | |
Q.all([ | |
getResolvedPromise(logger, "param1"), | |
getResolvedPromise(logger, "param2"), | |
getResolvedPromise(logger, "param3"), | |
Q.spread(["param4", "param5"], function(p, q) { | |
logger.log("in inner spread handler"); | |
return [p, q]; | |
}) | |
]).then(function(results) { | |
logger.log("in then handler"); | |
logger.log("return values from promises are in array - "); | |
logger.log(results); | |
}); | |
}); | |
TestRunnerReady("Test Case 4.5").then(function(logger) { | |
logger.log("combination of promises and spreads", true); | |
Q.all([ | |
getResolvedPromise(logger, "param1"), | |
getResolvedPromise(logger, "param2"), | |
getResolvedPromise(logger, "param3"), | |
Q.spread(["param4", "param5"], function(p, q) { | |
logger.log("in inner spread handler"); | |
return [p, q]; | |
}), | |
Q.spread(["param6", "param7"], function(p, q) { | |
logger.log("in inner spread handler"); | |
return [p, q]; | |
}) | |
]).spread(function(result1, result2, result3, result4, result5, result6, result7) { | |
logger.log("in outer spread handler"); | |
logger.log("return values from promises are captured in params - "); | |
logger.log("" + [result1, result2, result3, result4, result5, result6, result7].join(" ")); | |
}); | |
}); | |
TestRunnerReady("Test Case 4.6").then(function(logger) { | |
logger.log("spread internally calls Q.all (calling it can be skipped in chains)", true); | |
getResolvedPromise(logger, "param1") | |
.then(function(result) { | |
logger.log("in then handler"); | |
return [result, getResolvedPromise(logger, "param2")] | |
}) | |
.spread(function(result1, result2) { | |
logger.log("in spread handler "); | |
logger.log("" + [result1, result2].join(" ")); | |
}); | |
}); | |
TestRunnerReady("Test Case 4.7").then(function(logger) { | |
logger.log("combination of promises (including a rejected promise) with then handler", true); | |
Q.all([ | |
getResolvedPromise(logger, "param1"), | |
getRejectedPromise(logger, "param2"), /*rejected*/ | |
getResolvedPromise(logger, "param3"), | |
]).then(function(results) { | |
// won't execute this block | |
logger.log("in then handler"); | |
logger.log("return values from promises are in array - "); | |
logger.log(results); | |
}).fail(function (err) { | |
logger.log("in fail handler"); | |
logger.log("error - "); | |
logger.log(err); | |
}).fin(function () { | |
logger.log("in fin handler"); | |
}); | |
}); | |
TestRunnerReady("Test Case 4.8").then(function(logger) { | |
logger.log("combination of promises (including a rejected promise) with spread handler", true); | |
Q.all([ | |
getResolvedPromise(logger, "param1"), | |
getRejectedPromise(logger, "param2"), /*rejected*/ | |
getResolvedPromise(logger, "param3"), | |
]).spread(function(result1, result2, result3) { | |
// won't execute this block | |
logger.log("in spread handler"); | |
logger.log("return values from promises are captured in params - "); | |
logger.log("" + [result1, result2, result3].join(" ")); | |
}).fail(function (err) { | |
logger.log("in fail handler"); | |
logger.log("error - "); | |
logger.log(err); | |
}).fin(function () { | |
logger.log("in fin handler"); | |
}); | |
}); | |
TestRunnerReady("Test Case 4.9").then(function(logger) { | |
logger.log("combination of resolved and rejected promises", true); | |
Q.allSettled([ | |
getResolvedPromise(logger, "param1"), | |
getRejectedPromise(logger, "param2"), /*rejected*/ | |
getResolvedPromise(logger, "param3"), | |
]).then(function(results) { | |
var output = []; | |
results.forEach(function(result) { | |
if (result.state === "fulfilled") { | |
output.push(result.value); | |
} else { | |
logger.log("Reject promise " + result.reason); | |
} | |
}); | |
logger.log("Results - "); | |
logger.log(output); | |
}); | |
}); | |
//////////////////////////////////////////////////////////////////// | |
//////////////////////////////////////////////////////////////////// | |
//Ending the Chains | |
TestRunnerReady().then(function(logger) { | |
logger.group("5. ENDING THE CHAINS"); | |
}); | |
TestRunnerReady("Test Case 5.1").then(function(logger) { | |
logger.log("Exception goes uncaptured", true); | |
getResolvedPromise(logger) | |
.then(function(res) { | |
logger.log("throwing error in then"); | |
throw new Error("error in then handler"); | |
}).then(function(res) { | |
logger.log("in handler chain"); | |
}); | |
}); | |
TestRunnerReady("Test Case 5.2").then(function(logger) { | |
logger.log("Properly hanlding the exceptions in the then handlers (promise.fail, promise.done)", true); | |
getResolvedPromise(logger) | |
.then(function(res) { | |
logger.log("throwing error in then"); | |
throw new Error("error in then handler"); | |
}).then(function(res) { | |
logger.log("in handler chain"); | |
}).fail(function(e) { | |
logger.log("capture the error - "); | |
logger.log(e); | |
}).done(); | |
}); | |
//////////////////////////////////////////////////////////////////// | |
//////////////////////////////////////////////////////////////////// | |
// Beginning the promise chain (with custom methods as promises) | |
TestRunnerReady().then(function(logger) { | |
logger.group("6. BEGINNING THE CHAIN With custom methods as promises"); | |
}); | |
TestRunnerReady("Test Case 6.1").then(function(logger) { | |
logger.log("Creating promises on the fly and chaining then with regular promises (Q.fcall, promise.done)", true); | |
Q.fcall(function() { | |
logger.log("creating a promise"); | |
return "param1"; | |
}).then(function(param) { | |
logger.log(param); | |
return getResolvedPromise(logger, "param2"); | |
}).then(function(param) { | |
logger.log(param); | |
return Q.fcall(function() { | |
logger.log("creating a promise"); | |
return "param3"; | |
}) | |
}).done(function(param) { | |
logger.log(param); | |
logger.log("in done handler"); | |
}); | |
}); | |
TestRunnerReady("Test Case 6.2").then(function(logger) { | |
logger.log("Handling unhandled exceptions from promised wrapped methods (Q.fcall, promise.done)", true); | |
Q.fcall(function() { | |
logger.log("creating a promise"); | |
logger.log("throwing an exception"); | |
throw new Error("Exception from Q.fcall handler"); | |
return "param1"; | |
}).then(function(param) { | |
logger.log(param); | |
return getResolvedPromise(logger, "param2"); | |
}).fail(function(err) { | |
logger.log("in fail handler"); | |
logger.log(err); | |
}).fin(function() { | |
logger.log("in fin handler"); | |
}).done(function(param) { | |
logger.log("in done handler"); | |
}); | |
}); | |
//////////////////////////////////////////////////////////////////// | |
//////////////////////////////////////////////////////////////////// | |
// Examples of Promise-for-objects, Promise-for-methods, Promise-for-arrays | |
TestRunnerReady().then(function(logger) { | |
logger.group("7. Promise-for-objects, Promise-for-methods, Promise-for-arrays"); | |
}); | |
TestRunnerReady("Test Case 7.1").then(function(logger) { | |
logger.log("Retrieve properties of an object returned from a resolved promise (promise.get)", true); | |
Q.fcall(function() { | |
logger.log("Promise returns a custom object"); | |
return [{name: "Alice", age: 30}]; | |
}) | |
.get(0) | |
.get("name") | |
.then(function(name) { | |
logger.log("(promise.get): Received the name property of the custom object"); | |
logger.log(name); | |
}); | |
}); | |
TestRunnerReady("Test Case 7.2").then(function(logger) { | |
logger.log("Tweak properties of an object returned from a resolved promise (promise.get, promise.set)", true); | |
var customObj = [{name: "Alice", age: 30}]; | |
Q.fcall(function() { | |
logger.log("Promise returns a custom object"); | |
logger.log(customObj[0]); | |
return customObj; | |
}) | |
.get(0) | |
.set("name", "Bob") | |
.then(function(obj) { | |
logger.log("(promise.get and promise.set): Updated name from Alice to Bob"); | |
logger.log(customObj[0]); | |
}); | |
}); | |
TestRunnerReady("Test Case 7.3").then(function(logger) { | |
logger.log("Tweak properties of an object returned from a resolved promise (promise.get, promise.delete)", true); | |
var customObj = [{name: "Micky", age: 30}]; | |
Q.fcall(function() { | |
logger.log("Promise returns a custom object"); | |
logger.log(customObj[0]); | |
return customObj; | |
}) | |
.get(0) | |
.delete("age") | |
.then(function(obj) { | |
logger.log("(promise.get and promise.delete): Made Micky forever younger (removed age)"); | |
logger.log(customObj[0]); | |
}); | |
}); | |
TestRunnerReady("Test Case 7.4").then(function(logger) { | |
logger.log("Call methods on a object returned from a resolved promise (promise.send, promise.invoke, promise.post)", true); | |
var customObj = { | |
name: "Micky", | |
age: 30, | |
about: function() | |
{ | |
logger.log(["(promise.send) ", "My name is ", this.name, ". I am ", this.age, " years old."].join("")); | |
return this; | |
}, | |
getTraits: function (s1, s2, s3) { | |
logger.log(["(promise.invoke) ", "My traits are ", s1, " and ", s2].join("")); | |
return this; | |
}, | |
getFriends: function (f1, f2) { | |
logger.log(["(promise.post) ", "My friends are ", f1, " and ", f2].join("")); | |
return this; | |
} | |
}; | |
Q.fcall(function() { | |
logger.log("Promise returns a custom object"); | |
logger.log(customObj); | |
return customObj; | |
}) | |
.send("about") | |
.invoke("getTraits", "funny", "mischievous") | |
.post("getFriends", ["Donald", "Mini"]) | |
.done(function(obj) { | |
logger.log("Done calling all the methods"); | |
}); | |
}); | |
TestRunnerReady("Test Case 7.5").then(function(logger) { | |
logger.log("Execute a function returned by a resolved promise (promise.resolve(fn), promise.fcall, promise.fapply)", true); | |
var showContainerDeferred = Q.defer(); | |
var hideContainerDeferred = Q.defer(); | |
//resolve a promise that returns a custom method | |
showContainerDeferred.resolve(function (parentDivId, childDivId) { | |
logger.log("showContainerDeferred:" + ["parentdivid: ", parentDivId, " childDivId: ", childDivId].join("")); | |
}); | |
// Chain of promises that executes other promises | |
Q.fcall(function() { | |
logger.log("started a promise chain"); | |
}).then(function() { | |
showContainerDeferred.promise.fcall("parent1", "child1"); | |
hideContainerDeferred.promise.fcall("parent1", "child1"); | |
}).then(function() { | |
showContainerDeferred.promise.fapply(["parent2", "child2"]); | |
hideContainerDeferred.promise.fcall("parent2", "child2"); | |
}); | |
//resolve a promise that returns a custom method | |
hideContainerDeferred.resolve(function (parentDivId, childDivId) { | |
logger.log("hideContainerDeferred:" + ["parentdivid: ", parentDivId, " childDivId: ", childDivId].join("")); | |
}); | |
}); | |
TestRunnerReady("Test Case 7.6").then(function(logger) { | |
logger.log("Execute a function returned by a resolved promise (promise.resolve(fn), promise.fcall, promise.fapply)", true); | |
var showContainerPromise, hideContainerPromise; | |
//resolve a promise that returns a custom method | |
showContainerPromise = getResolvedPromise(logger, function (parentDivId, childDivId) { | |
logger.log("showContainerPromise:" + ["parentdivid: ", parentDivId, " childDivId: ", childDivId].join("")); | |
}, 100); | |
//resolve a promise that returns a custom method | |
hideContainerPromise = getResolvedPromise(logger, function (parentDivId, childDivId) { | |
logger.log("hideContainerPromise:" + ["parentdivid: ", parentDivId, " childDivId: ", childDivId].join("")); | |
}, 150); | |
// Chain of promises that executes other promises | |
Q.fcall(function() { | |
logger.log("started a promise chain"); | |
}).then(function() { | |
showContainerPromise.fcall("parent1", "child1"); | |
hideContainerPromise.fcall("parent1", "child1"); | |
}).then(function() { | |
showContainerPromise.fapply(["parent2", "child2"]); | |
hideContainerPromise.fcall("parent2", "child2"); | |
}); | |
}); | |
//////////////////////////////////////////////////////////////////// | |
//////////////////////////////////////////////////////////////////// | |
// Static methods | |
TestRunnerReady().then(function(logger) { | |
logger.group("8. Static methods - Q(value), Q.fcall, Q.fapply, Q.fbind, Q.delay, Q.resolve, Q.reject"); | |
}); | |
TestRunnerReady("Test Case 8.1").then(function(logger) { | |
logger.log("Q(value) or Q(promise)", true); | |
// composes a constant and a value from async op into Q chain | |
Q.all([Q("hello"), Q(getResolvedPromise(logger, "world"))]) | |
.spread(function(s1, s2) { | |
logger.log(s1 + " " + s2); | |
}) | |
.fail(function(err) { | |
logger.log(err); | |
}) | |
}); | |
TestRunnerReady("Test Case 8.2").then(function(logger) { | |
logger.log("Q.fcall - wraps a regular method and returns a promise", true); | |
Q.fcall(function() { | |
logger.log("regular function returns a promise"); | |
return getResolvedPromise(logger, function(a, b) { return a + b; }); | |
}) | |
.fcall(3, 5) | |
.then(function(result) { | |
logger.log("Result from an async op that return sum function: " + result); | |
}); | |
}); | |
TestRunnerReady("Test Case 8.3").then(function(logger) { | |
logger.log("Q.fapply - wraps a regular method and returns a promise", true); | |
Q.fcall(function() { | |
logger.log("regular function returns a promise"); | |
return getResolvedPromise(logger, function(a, b) { return a + b; }); | |
}) | |
.fapply([3, 5]) | |
.then(function(result) { | |
logger.log("Result from an async op that return sum function: " + result); | |
}); | |
}); | |
TestRunnerReady("Test Case 8.4").then(function(logger) { | |
logger.log("Q.fcall - Executes an eventually returned function from promise", true); | |
var asyncAddFn = getResolvedPromise(logger, function(a, b) { return a + b; }); | |
Q.fcall(asyncAddFn, 3, 5) | |
.then(function(result) { | |
logger.log("Result from an async op that return sum function: " + result); | |
}); | |
}); | |
TestRunnerReady("Test Case 8.5").then(function(logger) { | |
logger.log("Q.fapply - Executes an eventually returned function from promise", true); | |
var asyncAddFn = getResolvedPromise(logger, function(a, b) { return a + b; }); | |
Q.fapply(asyncAddFn, [3, 5]) | |
.then(function(result) { | |
logger.log("Result from an async op that return sum function: " + result); | |
}); | |
}); | |
TestRunnerReady("Test Case 8.6").then(function(logger) { | |
logger.log("Q.fbind - Returns promise by wrapping a method that may return data synchronously or asynchronously or throws an error", true); | |
var getCompanyPromise = Q.fbind(function (id) { | |
if (!id) { | |
throw new Error("id cannot be null"); | |
} | |
if (id === -1) { | |
return "anonymous company"; | |
} | |
return getResolvedPromise(logger, "Disney"); | |
}); | |
Q.fcall(getCompanyPromise) | |
.fail(function (error) { | |
logger.log("in fail handler"); | |
logger.log(error); | |
}); | |
Q.all([Q.fcall(getCompanyPromise, -1), Q.fcall(getCompanyPromise, 10)]) | |
.spread(function (company1, company2) { | |
logger.log(company1); | |
logger.log(company2); | |
}); | |
}); | |
} // end 'runQjsExamples' | |
Yeah, this is really useful, thanks for putting it together!
now i got it
https://gist.github.com/guptag/7205768#file-q-js-examples-L21 guess that should be value
thanks, fixed the typo.
Thank you so much for putting together such a helpful example. Excellent work.
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This is super useful :)